package com.hh.shirojwt.config;


import org.apache.shiro.web.filter.authc.BasicHttpAuthenticationFilter;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class JwtFilter extends BasicHttpAuthenticationFilter {


    /**
     * 执行登录认证
     *
     * @param request
     * @param response
     * @param mappedValue
     * @return
     */
    @Override
    protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) {
        try {
            executeLogin( request, response );
            return true;
        } catch (Exception e) {
            return false;
        }
    }

    /**
     *
     */
    @Override
    protected boolean executeLogin(ServletRequest request, ServletResponse response) throws Exception {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        String token = httpServletRequest.getHeader( "Authorization" );

        JwtToken jwtToken = new JwtToken( token );
        // 提交给realm进行登入，如果错误他会抛出异常并被捕获
        getSubject( request, response ).login( jwtToken );
        // 如果没有抛出异常则代表登入成功，返回true
        return true;
    }


    /**
     * 对跨域提供支持
     */
    @Override
    protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        httpServletResponse.setHeader( "Access-control-Allow-Origin", httpServletRequest.getHeader( "Origin" ) );
        httpServletResponse.setHeader( "Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE" );
        httpServletResponse.setHeader( "Access-Control-Allow-Headers", httpServletRequest.getHeader( "Access-Control-Request-Headers" ) );
        // 跨域时会首先发送一个option请求，这里我们给option请求直接返回正常状态
        if (httpServletRequest.getMethod().equals( RequestMethod.OPTIONS.name() )) {
            httpServletResponse.setStatus( HttpStatus.OK.value() );
            return false;
        }
        return super.preHandle( request, response );
    }
}